As a capacitor element for a high-frequency analog integrated circuit which is required to have a high-speed operation, an MIM (Metal-Insulator-Metal) capacitor element may be employed. The MIM capacitor element can have a more reduced parasitic resistance and parasitic capacitance than a MOS (Metal Oxide Semiconductor) capacitor element.
For example, Japanese Laid-open Patent Application Publication No. JP 2003-318269-A describes an MIM capacitor element. The MIM capacitor element includes a structure that has a lower electrode film made of aluminum copper (AlCu) formed on an interlayer insulating film, a dielectric film formed on the lower electrode film, and an upper electrode film formed on the dielectric film.
For example, Japanese Laid-open Patent Application Publication No. JP 2004-303908-A describes an MIM capacitor element. When an AlCu film formed on an interlayer insulating film that covers a substrate is patterned, wirings are formed on the interlayer insulating film and simultaneously an upper electrode of the MIM capacitor element is formed.
For example, Japanese Laid-open Patent Application Publication No. JP 2006-210952-A describes an MIM capacitor element with a structure similar to that described in Japanese Laid-open Patent Application Publication No. JP 2004-303908-A above. In the MIM capacitor element, a thickness of a capacitor lower electrode can be reduced thinner than a thickness of a capacitor upper electrode, and a contact connected to the capacitor lower electrode is formed in an underlying interlayer insulating film.
In the MIM capacitor elements described in Japanese Laid-open Patent Application Publications No. JP 2004-303908-A and No. JP 2006-210952-A above, the capacitor lower electrode, the capacitor insulating film, and the capacitor upper electrode have the same planar shape respectively.
Japanese Laid-open Patent Application Publication No. JP 2003-526927-A describes an MIM capacitor. The MIM capacitor has a capacitor lower electrode and a dielectric film, both having the same planar shape, and a capacitor upper electrode formed on the dielectric film to have a narrower planar shape than the dielectric film.